Characterization of an experimental setup for two-proton transfer reaction measurements on gaseous targets

Disagreement between theoretical nuclear matrix element calculations complicates the possible measurement of the unknown neutrino mass scale through observation of neutrinoless double-beta decay. These calculations each make simplifying assumptions, and in particular the Quasi-Random Phase Approximation (QRPA) technique generally proceeds from a description of the ground states of the relevant nuclei as condensates of 0+ nucleon pairs, in analogy to the BCS theory of superconductivity.   This can be tested by two-nucleon transfer reactions, which should then proceed mostly to the ground state of the residual nucleus.  The (³He,n) reaction has been carried out at a dedicated time-of-flight system at TUNL on several nuclei of interest to double-beta decay, including ¹³⁴Xe.  The latter measurements were carried out with a gas cell target, and preliminary results from benchmark measurements carried out with ⁴⁰Ar and ¹³⁶Xe will be shown and compared with previous measurements.  System performance, including timing resolution and background rates, will be discussed.